The RNF213 variant was observed in 21.4% (50 of 234) of patients with ICAS as well as 69.1% (199 of 288) of patients with MMD, but rarely in non-MMD, non-ICAS patients (3.6%, 5 of 137 patients) and healthy control patients (1.2%, 1 of 83 patients). Here, RNF213 is linked to familial isolated congenital asplenia.